suitable for welding using all of the known methods. However, arc welding should be preferred

over gas fusion welding.

Welding slag must be removed. Its presence will lead to high removal rates, especially for

Sulfurous oven gases, due to the formation of low-melting corrosion products.

Preheating and heat treatment after welding is generally unnecessary.

Filler Metals

Table 10

Base Metal

Electrode or Welding Rod

1.4878

1.4551/1.4829

1.4828

1.4829

1.4845

1.4842

1.4841

1.4842

1.4876

2.4806/2.4807

Product Range

We supply seamless hot-rolled and cold-processed pipes made of heat-resistant steels as well as

welded pipes with dimensions and tolerances based on DIN 2462 and DIN 2463.

Acceptance

An acceptance test certificate according to DIN 50049/3.1 can be made available for the

heat-resistant pipes. Acceptance is performed according to Steel-Iron Material Data Sheet 470.

DIN 2463/17457

<p><b>Pipes made of austenitic, heat-resistant steels</b></p><br><p>Heat-resistant steels were specially developed for use at high temperatures.</p><p>In the form of pipes, they are used in the construction of heat exchangers, for example.</p><br><br><p><b>Characteristics of heat-resistant steels</b></p><br><p>Heat-resistant steels are steels possessing good mechanical properties for short and long-term</p><p>loading due to their higher alloy content of chromium, nickel, silicon, and aluminium and with special</p><p>resistance to the effects of hot gases and combustion products as well as molten salt and metal at</p><p>temperatures above approximately 550&#176;C. The level of their resistance depends enormously on the</p><p>reaction conditions and cannot be determined using any test method.</p><br><br><p><b>Scaling Resistance in the Air</b></p><p><span class="tDescSmall">Table 1</span></p><table class="techDescTable"><thead><tr><th><b>Type of Steel</b></th><th><b>Material</b></th><th><b>Temperature*</b></th></tr> </thead><tbody><tr class="Even"><td>X12 CrNiTi18 9</td><td>1.4878</td><td>850&#176;C</td></tr><tr class="UnEven"><td>X15 CrNiSi 20 12</td><td>1.4828</td><td>1000&#176;C</td></tr><tr class="Even"><td>X 12 CrNi 25 21</td><td>1.4845</td><td>1050&#176;C</td></tr><tr class="UnEven"><td>X 15 CrNiSi 25 20</td><td>1.4841</td><td>1150&#176;C</td></tr><tr class="Even"><td>X 10 NiCrAlTi 32 20</td><td>1.4876</td><td>1100&#176;C</td></tr></tbody></table><br><br><p><b>Chemical Composition</b></p><p><span class="tDescSmall">Table 2</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b> C %</b></th><th><b>Si %</b></th><th><b>Mn max.</b></th><th><b>P max</b></th><th><b>S max</b></th><th><b>Al %</b></th><th><b>Cr %</b></th><th><b>Ni %</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>≤0.12</td><td>≤1.0</td><td>2.0</td><td>0.045</td><td>0.030</td><td><br></td><td>17.0-19.0</td><td>9.0-12.0</td></tr><tr class="UnEven"><td>1.4828</td><td>≤0.20</td><td>1.5-2.5</td><td>2.0</td><td>0.045</td><td>0.030</td><td><br></td><td>19.0-21.0</td><td>11.0-13.0</td></tr><tr class="Even"><td>1.4845</td><td>≤0.15</td><td>≤0.75</td><td>2.0</td><td>0.045</td><td>0.030</td><td><br></td><td>24.0-26.0</td><td>19.0-22.0</td></tr><tr class="UnEven"><td>1.4841</td><td>≤0.20</td><td>1.5-2.5</td><td>2.0</td><td>0.045</td><td>0.030</td><td><br></td><td>24.0-26.0</td><td>19.0-22.0</td></tr><tr class="Even"><td>1.4876</td><td>≤0.12</td><td>≤1.0</td><td>2.0</td><td>0.030</td><td>0.020</td><td>0.15-0.6</td><td>19.0-23.0</td><td>30.0-34.0</td></tr></tbody></table><br><hr><br><br><p>The scaling resistance the high-alloyed chromium-nickel steels is achieved using a</p><p>protective top layer consisting primarily of chromium oxide.</p><p>Additional additives, especially of aluminum and silicon, provide additional protection.</p><br><table class="techDescTable"><thead><tr><th><b>.</b></th></tr> </thead><tbody></tbody></table><br><p>Oxidation, sulfurization, carburization, nitrogenization, and reactions with ashes and</p><p>other solid or molten deposits are particularly important for the scaling resistance from</p><p>a technical standpoint. The reactions can occur individually or simultaneously depending</p><p>on the prevailing conditions and may have correspondingly different reaction rates.</p><br><table class="techDescTable"><thead><tr><th><b>..</b></th></tr> </thead><tbody></tbody></table><br><p>The scaling limit temperatures specified in Table 1 apply to air and are an approximation for</p><p>sulfur-free combustion gases. For high water vapor contents, the actual scaling limit may be lower.</p><p>For completely combusted, sulfur-free gases, a reduction of the scaling resistance by 100 to 200&#176;C</p><p>must be taken into account depending on the composition of the gas.</p><br><table class="techDescTable"><thead><tr><th><b>...</b></th></tr> </thead><tbody></tbody></table><br><p>In combustion gases containing sulfur, there is no significant impact on the scaling resistance</p><p>when a surplus of air is available.</p><p>In complete combusted, sulfurous gases, though, the scaling limit is significantly reduced</p><p>due to the formation of sulfide. Alloys with high nickel contents can exhibit strong scaling</p><p>above the nickel-nickel sulfide eutectic point, which is approx. 640&#176;C.</p><br><table class="techDescTable"><thead><tr><th><b>....</b></th></tr> </thead><tbody></tbody></table><br><p>When exposed to incompletely combusted gases, carburization of the heat-resistant</p><p>steels can occur. In this case, bonding with chromium can result in the depletion of this</p><p>element as a mixed crystal, which is indicated by a reduced scaling resistance.</p><p>The austenitic chromium-nickel steels, especially those with a high nickel content, are less</p><p>sensitive than the corresponding ferritic chromium steels.</p><br><table class="techDescTable"><thead><tr><th><b>.....</b></th></tr> </thead><tbody></tbody></table><br><p>For reductive combustion gases containing nitrogen, the behavior of the steel is similar</p><p>to that during carburization.</p><br><hr><br><br><p>For deposits from the combustion gases, low-melting eutectics can form on the steel</p><p>due to reaction with the scale layer, which quickly leads to the destruction of</p><p>the material. The permissible temperature limits depend greatly in this case on the</p><p>composition of the deposits and are generally very low, for example like when</p><p>alkaline sulfates, phosphates, metals and/or heavy metal oxides are present.</p><p>Sulfidation is increased the most by hydrogen sulfide. Aluminum and silicon</p><p>improve resistance against sulfidation.</p><p>Nickel and silicon Improve the carburization resistance.</p><br><table class="techDescTable"><thead><tr><th><b>.</b></th></tr> </thead><tbody></tbody></table><br><p>When starting up and shutting down systems and during downtimes, combustion products may</p><p>condense. If this condensate contains sulfurous acid or sulfuric acid, then you must</p><p>expect a stronger reaction.</p><br><table class="techDescTable"><thead><tr><th><b>..</b></th></tr> </thead><tbody></tbody></table><br><p>Heat-resistant steels are generally used at temperatures at which the material creeps when</p><p>stressed. When calculating for systems, you must use the creep strength and elongation time</p><p>values provided in Table 4.</p><br><br><p><b>Comparison of Standards</b></p><p><span class="tDescSmall">Table 3</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b>AISI</b></th><th><b>AFNOR</b></th><th><b>UNI</b></th><th><b>GOST</b></th><th><b>SBB*</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>321</td><td>Z 6 CNT 18-10</td><td>X 6 CrNiTi1811</td><td>12 Ch 48 N 10 T</td><td>A700</td></tr><tr class="UnEven"><td>1.4828</td><td>309</td><td>Z15 CNS 20-12</td><td>-</td><td>20 Ch 20 N 14 S 2</td><td>H550</td></tr><tr class="Even"><td>1.4845</td><td>310S</td><td>Z12 CN 25-20</td><td>X 22 CrNi 25 20</td><td>-</td><td>H522</td></tr><tr class="UnEven"><td>1.4841</td><td>314</td><td>Z 12 CNS 25-20</td><td>X 16 CrNiSi 25 20</td><td>20 Ch 25 N 20 S 2</td><td>H525</td></tr><tr class="Even"><td>1.4876</td><td>-</td><td>Z 8 NC 32-21</td><td>-</td><td>ChN 32 T</td><td>H500</td></tr></tbody></table><p><span class="tDescSmall">(*)=Manufacturer&#39;s Code Sch&#246;ller-Bleckmann B&#246;hler</span></p><br><hr><br><br><p>When using heat-resistant steels, you must expect changes in the material in certain temperature</p><p>ranges that, after cooling down to room temperature, can lead to a reduction of the ductility.</p><p>The behavior of the material at the operating temperature is generally not affected by this.</p><br><br><p><b>Mechanical Properties</b></p><p><span class="tDescSmall">Table 4</span></p><table class="techDescTable"><thead><tr><th><b>Type of Steel</b></th><th><b>Hardness</b></th><th><b>Elastic Limit*</b></th><th><b>Tensile Strength</b></th><th><b>Fracture Elongation**</b></th></tr> </thead><tbody><tr class="Even"><td>(Material)</td><td>(HB)</td><td>(N/mm&#178;)</td><td>(N/mm&#178;)</td><td>(L0=5Da longitudinally)</td></tr><tr class="UnEven"><td>1.4878</td><td>130-190</td><td>min. 210</td><td>500-750</td><td>min. 40%</td></tr><tr class="Even"><td>1.4828</td><td>150-210</td><td>min. 230</td><td>500-750</td><td>min. 30%</td></tr><tr class="UnEven"><td>1.4845</td><td>130-190</td><td>min. 210</td><td>500-750</td><td>min. 35%</td></tr><tr class="Even"><td>1.4841</td><td>150-210</td><td>min. 230</td><td>550-800</td><td>min. 30%</td></tr><tr class="UnEven"><td>1.4876</td><td>139-190</td><td>min. 210</td><td>500-750</td><td>min. 30%</td></tr></tbody></table><p><span class="tDescSmall">The values apply to cold formed pipes with wall thicknesses of 0.5 to 5 mm</span></p><p><span class="tDescSmall">(*)=0.2% elastic limit</span></p><p><span class="tDescSmall">(**)=The values apply to sample thicknesses ≥ 3 mm.</span></p><br><br><p>In austenitic steels with higher Cr content, the Ω phase can form the temperature range from 550</p><p>to 900&#176;C. The Ω phase is a brittle, intermetallic compound between iron and chromium and other</p><p>transition metals that do not exhibit any non-permissible changes to the ductility at operating</p><p>temperatures, but that can cause the material to become brittle after cooling down to room</p><p>temperature. Si and Cr promote these precipitation processes, while Ni and Al hinder them.</p><p>The Ω phase is only relevant in actual practice for 1.4821 and 1.4841.</p><p>The Ω phase can be dissolved again by annealing at temperatures &gt; 900&#176;C.</p><br><hr><br><br><p><b>Characteristic values of the long-term behavior at high temperatures</b></p><br><p>1% Elastic Limit*</p><p><span class="tDescSmall">Table 5</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b>Temperature</b></th><th><b>for 1,000h</b></th><th><b>for 10,000h</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>600 &#176;C</td><td>110 N/mm&#178;</td><td>85 N/mm&#178;</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>45</td><td>30</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>15</td><td>10</td></tr><tr class="UnEven"><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="Even"><td>1.4828</td><td>600 &#176;C</td><td>120</td><td>80</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>50</td><td>25</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>20</td><td>10</td></tr><tr class="UnEven"><td><br></td><td>900 &#176;C</td><td>8</td><td>4</td></tr><tr class="Even"><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="UnEven"><td>1.4841</td><td>600 &#176;C</td><td>150</td><td>105</td></tr><tr class="Even"><td><br></td><td>700 &#176;C</td><td>53</td><td>37</td></tr><tr class="UnEven"><td><br></td><td>800 &#176;C</td><td>23</td><td>12</td></tr><tr class="Even"><td><br></td><td>900 &#176;C</td><td>10</td><td>5.7</td></tr><tr class="UnEven"><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="Even"><td>1.4876</td><td>600 &#176;C</td><td>130</td><td>90</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>70</td><td>40</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>30</td><td>15</td></tr><tr class="UnEven"><td><br></td><td>900 &#176;C</td><td>13 N/mm&#178;</td><td>5 N/mm&#178;</td></tr></tbody></table><p><span class="tDescSmall">(*)=The stress, based on the initial diameter, that leads to a permanent elongation of 1% </span></p><p><span class="tDescSmall">after 1,000 or 10,000 h</span></p><br><br><p>Creep Strength*</p><p><span class="tDescSmall">Table 6</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b>Temperature</b></th><th><b>for 1,000h</b></th><th><b>for 10,000h</b></th><th><b>for 100,000h</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>600 &#176;C</td><td>185 N/mm&#178;</td><td>115 N/mm&#178;</td><td>65 N/mm&#178;</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>80</td><td>45</td><td>22</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>35</td><td>20</td><td>10</td></tr><tr class="UnEven"><td><br></td><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="Even"><td>1.4828</td><td>600 &#176;C</td><td>190</td><td>120</td><td>65</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>75</td><td>36</td><td>16</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>35</td><td>18</td><td>7.5</td></tr><tr class="UnEven"><td><br></td><td>900 &#176;C</td><td>15</td><td>8.5</td><td>3</td></tr><tr class="Even"><td><br></td><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="UnEven"><td>1.4841</td><td>600 &#176;C</td><td>230</td><td>160</td><td>80</td></tr><tr class="Even"><td><br></td><td>700 &#176;C</td><td>80</td><td>40</td><td>18</td></tr><tr class="UnEven"><td><br></td><td>800 &#176;C</td><td>35</td><td>18</td><td>7</td></tr><tr class="Even"><td><br></td><td>900 &#176;C</td><td>15</td><td>8.5</td><td>3</td></tr><tr class="UnEven"><td><br></td><td><br></td><td><br></td><td><br></td><td><br></td></tr><tr class="Even"><td>1.4876</td><td>600 &#176;C</td><td>200</td><td>152</td><td>114</td></tr><tr class="UnEven"><td><br></td><td>700 &#176;C</td><td>90</td><td>68</td><td>47</td></tr><tr class="Even"><td><br></td><td>800 &#176;C</td><td>45</td><td>30</td><td>19</td></tr><tr class="UnEven"><td><br></td><td>900 &#176;C</td><td>20 N/mm&#178;</td><td>11 N/mm&#178;</td><td>4 N/mm&#178;</td></tr></tbody></table><p><span class="tDescSmall">(*)=The stress, based on the initial diameter, that leads to breakage after 1,000, 10,000 or 100,000 h.</span></p><br><hr><br><br><p><b>Physical Properties</b></p><br><p>Average linear coefficient of expansion between 20&#176;C and ...</p><p><span class="tDescSmall">Table 7</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b>...400&#176;C</b></th><th><b>...800&#176;C</b></th><th><b>...1000&#176;C</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>18.00</td><td>19.00</td><td>-</td></tr><tr class="UnEven"><td>1.4828</td><td>17.50</td><td>18.50</td><td>19.50</td></tr><tr class="Even"><td>1.4845</td><td>17.00</td><td>18.00</td><td>19.00</td></tr><tr class="UnEven"><td>1.4841</td><td>17.00</td><td>18.00</td><td>19.00</td></tr><tr class="Even"><td>1.4876</td><td>16.00</td><td>17.50</td><td>18.50</td></tr></tbody></table><p><span class="tDescSmall">(10⁻⁶ mm) : (m x &#176;C)</span></p><br><br><p>Thermal Conductivity</p><p><span class="tDescSmall">Table 8</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b> 20&#176;C</b></th><th><b>500&#176;C</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>0.15</td><td>0.21</td></tr><tr class="UnEven"><td>1.4828</td><td>0.15</td><td>0.21</td></tr><tr class="Even"><td>1.4845</td><td>0.14</td><td>0.19</td></tr><tr class="UnEven"><td>1.4841</td><td>0.14</td><td>0.19</td></tr><tr class="Even"><td>1.4876</td><td>0.12</td><td>0.19</td></tr></tbody></table><p><span class="tDescSmall">(W) : (cm x &#176;C)</span></p><br><br><p>Other Characteristic Values</p><p><span class="tDescSmall">Table 9</span></p><table class="techDescTable"><thead><tr><th><b>Material</b></th><th><b>Density*</b></th><th><b>Specific Heat**</b></th><th><b>p***</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>7.9</td><td>0.50</td><td>0.75</td></tr><tr class="UnEven"><td>1.4828</td><td>7.9</td><td>0.50</td><td>0.85</td></tr><tr class="Even"><td>1.4845</td><td>7.9</td><td>0.50</td><td>0.85</td></tr><tr class="UnEven"><td>1.4841</td><td>7.9</td><td>0.50</td><td>0.90</td></tr><tr class="Even"><td>1.4876</td><td>8.0</td><td>0.50</td><td>1.00</td></tr></tbody></table><p><span class="tDescSmall">(*)=g/cm&#179;</span></p><p><span class="tDescSmall">(**)=J : (g x &#176;C)</span></p><p><span class="tDescSmall">(***)=Specific electrical resistance for (O x mm&#178;) : m</span></p><br><hr><br><br><p><b>Processing</b></p><br><p>Heat-resistant austenitic CrNi steels are characterized by a high temperature strength in addition</p><p>to their good scaling resistance. For this reason, they can generally be used for purposes in which</p><p>a high mechanical strength is required in addition to scaling resistance.</p><p>The high temperature strength of the material 1.4876 is improved through the addition of titanium</p><p>and aluminum so that the long-term values for this material at temperatures over 600&#176;C are</p><p>comparatively high.</p><br><table class="techDescTable"><thead><tr><th><b>.</b></th></tr> </thead><tbody></tbody></table><br><p>Due to the NI content, these steels are more sensitive to sulfurous gases, especially in</p><p>non-oxidizing atmospheres. On the other hand, they have better resistance to carburization</p><p>and nitrogenization in comparison to ferritic steels.</p><p>The material 1.4841 should not be used in continuous operation at temperatures below 900&#176;C</p><p>due to its tendency to become brittle in the Ω phase.</p><br><table class="techDescTable"><thead><tr><th><b>..</b></th></tr> </thead><tbody></tbody></table><br><p>It should only be necessary in a few cases for the user to hot-form the heat-resistant</p><p>austenitic steels.</p><p>The hot forming temperature is 1150 - 800&#176;C.</p><br><table class="techDescTable"><thead><tr><th><b>...</b></th></tr> </thead><tbody></tbody></table><br><p>Due to their low yield strength and high elasticity, austenitic steels have good</p><p>cold forming properties. After very strong deformation, the resulting cold hardening</p><p>effects can be undone through subsequent heat treatment with fast quenching.</p><br><table class="techDescTable"><thead><tr><th><b>....</b></th></tr> </thead><tbody></tbody></table><br><p>Annealing the austenitic steels at 900&#176;C air temperature offers advantages</p><p>In terms of cutting operations over the quenched state.</p><p>In solution annealing, the steel is cooled in water or air, and for thinner walls,</p><p>in air or inert gas.</p><br><table class="techDescTable"><thead><tr><th><b>.....</b></th></tr> </thead><tbody></tbody></table><br><p>When machining austenitic steels, adequate cooling must be ensured due to their low thermal</p><p>conductivity. Its strong cold hardening behavior, which can make the use of dull tools or machining</p><p>at the cutting depth more difficult, requires the use of sharper tools and the correct specification of</p><p>the cutting depth and cutting speed.</p><br><hr><br><br><p><b>Welding</b></p><br><p>The heat-resistant austenitic steels are, assuming the corresponding qualifications are available,</p><p>suitable for welding using all of the known methods. However, arc welding should be preferred</p><p>over gas fusion welding.</p><br><p>Welding slag must be removed. Its presence will lead to high removal rates, especially for</p><p>Sulfurous oven gases, due to the formation of low-melting corrosion products.</p><br><p>Preheating and heat treatment after welding is generally unnecessary.</p><br><br><p>Filler Metals</p><p><span class="tDescSmall">Table 10</span></p><table class="techDescTable"><thead><tr><th><b>Base Metal</b></th><th><b>Electrode or Welding Rod</b></th></tr> </thead><tbody><tr class="Even"><td>1.4878</td><td>1.4551/1.4829</td></tr><tr class="UnEven"><td>1.4828</td><td>1.4829</td></tr><tr class="Even"><td>1.4845</td><td>1.4842</td></tr><tr class="UnEven"><td>1.4841</td><td>1.4842</td></tr><tr class="Even"><td>1.4876</td><td>2.4806/2.4807</td></tr></tbody></table><br><br><table class="techDescTable"><thead><tr><th><b>Product Range</b></th></tr> </thead><tbody></tbody></table><p>We supply seamless hot-rolled and cold-processed pipes made of heat-resistant steels as well as</p><p>welded pipes with dimensions and tolerances based on DIN 2462 and DIN 2463.</p><br><br><table class="techDescTable"><thead><tr><th><b>Acceptance</b></th></tr> </thead><tbody></tbody></table><p>An acceptance test certificate according to DIN 50049/3.1 can be made available for the</p><p>heat-resistant pipes. Acceptance is performed according to Steel-Iron Material Data Sheet 470.</p>